1. Field of the Invention
The present invention relates to a method for controlling an optical input device, and more particularly, to a method for adjusting an operation frequency of an optical input device according to a change of a reference frame.
2. Description of the Prior Art
Recently, optical input devices, such as optical mouses, have become popular due to their accuracy and convenience in use. Furthermore, as wireless technology keeps growing, more and more optical input devices transmit data wirelessly. Generally, a wireless optical device is powered by a battery. However, the capacity of a battery is limited and needs to be replaced or recharged periodically. Therefore, how to reduce power consumption of a wireless optical input device becomes a major topic. To save power of a wireless optical input device, U.S. Pat. No. 6,455,840 discloses a method for automatically adjusting a sampling frequency of an image sensor by computing an equivalent moving speed of the wireless optical input device, when the equivalent moving speed of the wireless optical input device is decreased, the sampling frequency of the image sensor is reduced; when the equivalent moving speed of the wireless optical input device is increased, the sampling frequency of the image sensor is increased as well. However, because the wireless optical input device further needs a related circuit to compute the equivalent moving speed, the circuitry of the wireless optical input device becomes more complex, and thus restricts the applications of the method of the prior art.